1. Field of the Invention
The present invention relates to a multi-stage storage case for cassettes for specimens for histopathological examination, or for sorting, storing or transporting cassette blocks made by setting the aforementioned specimen in the cassette using paraffin before or after cutting into slices for microscopic examination.
2. Description of the Prior Art
Hitherto, this kind of multi-stage storage case was made of a synthetic resin such as ABS resin and, as seen from FIGS. 9 and 10, its construction was such that the case housing 1 was made of a plurality (usually 6) of shelf units 2 and each shelf unit 2 has housed therein freely slidably a drawer 3, in which cassettes (or cassette blocks) 4 were stored. A pair of (left and right) indented stoppers 6 were formed under the front edge portion of a top unit 5 and shelf units 2, the rear wall 7 of each drawer 3 has formed thereon a pair of (left and right) projections 8 engageably with and disengageably from the indented stoppers 6 so as to ensure against sliding out of the drawer 3 (See FIG. 10.).
With a conventional multi-stage storage case as described above, there was an inconvenience of necessarily using one whole case even for transportation of a small number of cassettes 4 for which one or two drawers 3 suffices. Another problem was that when it suffices to pull out drawers 3 only partly to take in or take out the wanted number of cassettes 4, the drawer 3 partly pulled out inclined with the front end down, this resulting in spontaneous sliding of the drawer with its own weight and that of the cassettes 4 therein and possibly sliding completely out of the case to drop because of the disconnection of the projections 8 from the indented stoppers 6.